I was looking over the most recent version of source for this widget as I'm migrating to jQ-UI 1.10, and I noticed that $next on the title line doesn't have a var declaration next to it. I compared against an older version of the code, and it looks like it just lost it when all the repeated var statements were added.
It's a minor bug, but I thought you'd like to know about it.
scope a leaky var. fixes #403